Are companies ready for the new activist shareholder?

FORTUNE — Exposing fibs, exaggerations and indiscretions — routinely used to undercut or derail political careers — is migrating to the corporate world as a new tactic for unhappy shareholder activists to win changes they seek in the executive suite.

Disclosure of a falsehood in Yahoo YHOO chief executive Scott Thompson’s resume resulted in his departure from the company, and put a new, more personal, face on tactics to effect corporate shake-ups. A noticeable number of top-level executives have been booted when skewed relationships with subordinates came to light, and others have been felled by professional failings.

But exposing discrepancies in Thompson’s academic record provides a new avenue for activist investors and hedge funds to root around in past professional, academic, and perhaps even personal, events or omissions to ferret out discrepancies.

“It’s a new tactic because typically it’s been boards that uncovered fabrications rather than shareholders,” says Paul Hodgson, senior researcher for GMIRatings, a corporate governance research firm.

“Anything that goes to the integrity of the individual is appropriate to examine, whether it was a mistake or an intention to deceive,” says Robert McCormick, chief policy officer of Glass Lewis, a San Francisco-based proxy advisor. “His degree is part of a skill set that he brought to the job.”

Christopher Bayer, co-founder and blogger at TheShareholderActivist.com, says Thompson’s dissembling was “a complete violation of confidence and a betrayal. Trust is priceless, and today there is no room for error. The public is not forgiving.”

Examining credentials “is much needed, especially because so much is fudged, shaded, and manipulated in the corporate world. There is also a certain amount of resumes that are less than totally accurate,” says Bayer, a psychiatrist who specializes in treating Wall Street professionals and their families.

The Thompson episode “encourages investors that it may be worth doing better background checks, and boards need to do a better job vetting candidates,” says Stephen Bainbridge, a law professor at UCLA.

Thompson listed that he had earned a degree in computer science from Stonehill College, outside Boston, but his earlier resume at former employer eBay’s PayPal unit had only included a degree in accounting from that college.

In general, shareholders are more alert to governance issues after the 2008 financial meltdown, a concern inflamed by J.P. Morgan Chase’s recent huge hedging losses. Once-passive shareholders are exploring new ways to unlock corporate accountability, including disclosure of how much companies spend on political spending and lobbying.

With corporate dollars now able to fuel political action committees, following the 2010 Citizens United ruling by U.S. Supreme Court, more investor groups are starting to ask for transparency on such spending.

According to ProxyMonitor.org, operated by the Manhattan Institute, which tracks shareholder proposals, a plurality of all proposals introduced to date this proxy season call for more corporate disclosure of political spending or lobbying. However, forging ahead with more CEO-centered tactics may have to wait since the proxy season, which began around mid-April, ends in the middle of next month.

But CEO choices and political leanings will come under greater scrutiny as shareholders seek greater detail about campaign contributions and lobbying expenses, and whether they align with corporate interests or personal preferences. A recent report by the shareholder tracking organization, As You Sow, found that most corporations have not been disclosing details of their campaign contributions and lobbying expenses.

“I think we will see continued attention to and parsing of political campaign donations,” predicts Bainbridge.

Shareholder activists may also call for additional say on executive compensation, more diversity among directors, replacing ineffective directors, and more transparency on company factory conditions and the use of child labor. Also on the agenda, in cases like J.P. Morgan, is splitting the office of chief executive and chairman in companies where executives like Jamie Dimon hold both posts.

Such challenges recently have come not only from labor union pension funds but also from some less likely places, like religious groups, which typically have not been bird-dogging executive resumes — to try to shape how executive pay packages are awarded. For two years, the Sisters of St. Francis of Philadelphia, the Nathan Cummings Foundation, and other religious institutions that own Goldman Sachs shares pushed proposals to review executive pay.

Such proposals have rallied only a tiny slice of shareholder support, but the effort to disclose pay ratios between executives and employees garnered a flurry of public attention when it was introduced last year. An effort to bring it to a shareholders’ vote this year was derailed when the Securities and Exchange Commission decided Goldman already had addressed the issue.

The ProxyMonitor.org Score Card, which tracks shareholder proposals at large companies, reports that initial proxy filings turned up somewhat fewer shareholder proposals aimed at social or political goals unrelated to executive compensation. Many companies, in the wake of the federal Dodd-Frank law, already have committed to review executive compensation on an annual basis.

Bad performance at publicly held companies does not always mean that the chief executive is on the chopping block, but as we have seen with Yahoo, finding a salacious gem in an executive’s background can ignite enough disgruntlement to force change.

In Thompson’s case, his resume-padding came as shareholders were increasingly dissatisfied with Yahoo’s inability to steer an effective, long-term business course. The discovery of his altered credentials by activist hedge fund Third Point sealed his departure. Third Point, run by investor Daniel Loeb, who will be joining the Yahoo board, did not return a phone call for an interview.

Boards of directors, which routinely delegate vetting to outside executive recruiters, may need “to beef up their efforts,” notes Hodgson. “The boards look foolish, and the company suffers reputational damage when they hire an unsuitable CEO. Plus it’s expensive to hire and fire the CEO; it costs the shareholders.”

McCormick warns, though, that such investigations “raise the specter of looking into backgrounds, as far as back as high school, of executives and board members that could lead to overreaching.

“In politics, there is so much scrutiny that it chills the willingness of many to take part,” he adds. “If it goes too far, it will be open season on executives.”